1. Field of the Invention
The present invention relates to an installation structure for a loudspeaker system in a vehicle, the installation structure enabling an occupant to hear sound emitted from the loudspeaker system as sound coming from the front of the interior of the vehicle (hereinafter, referred to as a “vehicle interior”).
2. Description of the Related Art
An in-vehicle loudspeaker system disclosed in Japanese Unexamined Patent Application Publication No. 4-223697 has been known. The in-vehicle loudspeaker system includes a woofer placed under a back seat in a vehicle interior. The woofer is connected to an acoustic tube which extends from the woofer to a space under a dashboard positioned in the front of the vehicle interior. In the in-vehicle loudspeaker system having such a configuration, sound generated from the woofer passes through the acoustic tube and is then output from the space under the dashboard to the vehicle interior. Consequently, an occupant in the vehicle interior can hear low-frequency sound emitted from the woofer as sound coming from the front of the vehicle interior when the woofer is not placed inside the dashboard, in which various instruments and in-vehicle devices, such as a navigation system and an audio system, are arranged, positioned in the front of the vehicle interior.
In the above-described related-art in-vehicle loudspeaker system (or an installation structure for a woofer in a vehicle), however, since the woofer is placed under the back seat in the vehicle interior, the acoustic tube extending from below the back seat to the space under the dashboard in the front of the vehicle interior is long, namely, the acoustic tube has a large-scale structure. Although a loudspeaker system may be installed inside the dashboard, it is difficult to install a low-frequency loudspeaker system inside the dashboard which accommodates instruments and in-vehicle devices, such as a navigation system and an audio system, because such a low-frequency loudspeaker system, particularly, a subwoofer has a large size.